High-pressure rotary pump



March 31, 1925. 1,531,607

' T. W. GREEN HIGH PRESSURE ROTARY PUMP Fild Jan. 24, 1925 aSheets-Sheet 1 .March 31. 1925. 1,531,607

T. W. GREEN HIGH PRESSURE ROTARY PUMP Filed Jan. 24, 1923 5 Sheets-Sheet2 25 I F 4 i fl o o .25 O W .O i?

March 31.1925. 1,531,607

T. W. GREEN HIGH PRESSURE ROTARY PUMP Filed Jan. 24, 192:5 3 Shets-Sheet:5

Patented Mar. 31 1925.

UNITED STATES THOMAS w. GREEN, 01E PHILADELPHIA, PENNSYLVANIA.

HIGH-PRESSURE ROTARY PUMP.-

Application filed January 24, 1923. Serial No. 614,507.

To all whom it may concern:

Be it known that I, THOMAS WV. GREEN, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented a certain new and useful High-PressureRotary Pump, of whichv the following is a specification.

My invention relates to multiple stage rotary pumps adapted for use inpumping or compressing fluids and semi-fluids. To indicate the rangewhich it will handle I mention ether, gas, air, water, molasses, oil,grease, paint and tar.

The purpose of my invention is to provide a rotary pump of the characterindicated which is at once adapted to meet adeguately the needs ofservice and to easy an inexpensive manufacture.

A further purpose is to make an improved rotary multi-stage pump upon asingle pair of shafts, the individual stages comprising cooperatingencased pairs of impellers of the Root type, all upon the same pair ofshafts.

A further purpose is to provide a novel form of pump casing and newmeans for temperature regulation between stages.

Further purposes will appear in the speciiication and in the claims.

I have preferred to illustrate my invention by but one form, selecting aform that is simple and easily accessible, and efficient in operationand which well illustrates the principles involved.

Figures 1, 2 and 3 are respectively a plan view and side and endelevations of the preferred form of my invention. 4 Figure 4 is asectional end elevation take upon line 4-4 of Figure 5.

Figure 5 is a sectional side elevation taken upon line 55 of Figure 4.

Figures 6 and 7 are respectively front and end elevations of the centralsupporting member.

Figure 8 is a section upon the line 88 of Figure 6.

Figure 9 is an end elevation of a detail.

Figure 10 is a section on the line 10-10 of Figure 9.

Like numerals refer to like parts in all the drawings.

Describing in illustration and not in l1m1- tation and referring to thedrawings Prior to my resent invention, patents have been grants uponsingle stage pumps vented by me and shown in United States I 'at ent No. 1,046,77 3.

It is frequently desirable to pump a ainst pressures greater than arereadily o tainable by these single stage pumps, and also desirable toprogressively regulate the temperature during passage through the pump.

Thus, when used to furnish a supply of compressed air or other gas, therequisite power consumption for compression is materially reduced byprogressive cooling during compression; and again when used to pumpviscous fluids such as molasses and tar it is desirable to heat thefluid to make it flow more easil and also to have the im eller blades ata iigher temperature than t at of the fluid in order to reduce theextent to which the viscous fluid sticks to the blades.

In the form illustrated, a series of pairs of impellers, 15, 16, 16',17, 17 and 18, 18, encased to form a series of individual single stagepumps, are mounted upon and spaced along the parallel shafts 19 and 19.

Spaces are provided between the casings or enclosures 20, 21, 22 and 23Within which the impellers of successive single stage pumps operate. Theend walls (transverse to the impeller shafts) of adjoining casings orenclosures form the end walls of these spaces.

These spaces provide for conduit connection between the successive pumpsfrom the inlet 24 of the first pump to the outlet 25 of the last.

Each of the spaces is split up into central and end compartments. Thecentral compartments 26, 27, 28 respectively lie between vertical planesthrough the shafts and through these central compartments the fluid ispumped. The side or end compartments 29, '30 are shut oil from thecentral compartments by partition walls 31, 32 so that each compartment:29, between its partition walls and the outside walls 33 may becomplete in itself to receive heating or cooling fluid for theregulation of the temperature of the fluid passing through thesuccessive stages of the pump.

This heating or cooling fluid affects the fluid pumped not only duringthe time the latter is passing through the spaces but 4 while it isbeing pumped from one space 47 of a casing to another.

In order that impellers and casin and shafts may be very easilyaccessible or-inspection, removal or replacement, I provide forseparation along the axes of the shafts, thus separating the stationarypart. of the apparatus into a middleortion 34 between the shafts andremovab e semi-cylindrical portions 35 and 36 upon either side of themiddle portion.

The outer portions 35 and 36, made removable to provide easyaccessibility to any part of the interior, may com rise integralcastings each, extendin the ength of the ump structure, but pre erablare made up in sections, 37, 38, 39 40 an 41 as shown in the formillustrated. Each of the intermediate sections of the outer portions(Fig. 10 includes an inwardly-facing semi-cylindrical shell to completethe operating chamher for one of the impellers and an intermediate fluidcompartment for temperature regulation. The end section 37 acts as ashell only for the impeller chamber and the section 41 carries a heatingor cooling chamber.

The middle member 34 may also be made either integral or in sections.Usually I prefer to make it an integral casting. This middle membercomprises the main sup ort for the whole apparatus, and is widene at theends 42 and 43 to make the support more stable. The member 34 presentshalf housings 44 for the bearings 45 of the shafts and as an upperportion 46 and a lower portion for the gears 48.

This mem er also carries the half housings 49 for the glands 50 and themiddle ortions of the end casing walls of the diferent pairs ofimpellers. It forms a series conduit from the inlet of the first pump tothe outlet of the last, and, both reservoir and outlet at 51, 52 for thetemperature control compartments.

The operation of the individual pumps is well illustrated in Figures 4and 5. The synchronously rotating impellers seal in front and in rearand radially in part against the respective walls of their caslngs. Inthe middle they radially seal against one another along strips ofbabbitt 53 dovetailed along each side of each blade. Successive chargesof air, or of other fluid pumped, entrain at 54 between the outersemi-cylindrical walls and successive airs of blades and are thus sweptto the delivery side of the pump, at 55, whence they travel across theto s 56 of the partitions, down along the series conduit between theshafts and across the bottoms 57 of the opposite partitions to the inletof the next pump, and so on from pump to ump with pro gressively greatercompression until finally delivered from the out et" of the last pump.

. The babbitt seal ofeach impeller against its mate provides a close inrfitt' and sealing between the impellers of'eac pair permitting highimpeller velocities of rotation without material wear. -Such wear asdoes take place is, moreover, at the intermeshing gears rather than atthe. impellers.

The lmpellers are keyed to the shafts at 58 and the-blades are hollowedfor the sake of eater lightness.

e removable ortions of the bearing housings are provi ed with usualdowels for greater ease 1n accurate placement and are eld in place bystud bolts.

Leaka e alon the shafts is prevented by the lands 50 e bearingsthemselves are re erably of the Hyatt type which is well- Known andtherefore not here specifically described. The usual caps 59 at theouter ends of the bearings prevent undue loss of oil at the bearings.

In the illustrations the widths of successive pairs of impellers (alontheir axes) is made progressively sma ler by reason of progressivecompression of the pumped fluid. This is preferably the arrangement whenthe pumped fluid is air or other gas in that the specific volume of theair or other gas progressively diminishes with successive compressions.Obviously however, when the multistage pump is for use with fluidssubstantially incompressible such as water or molasses or grease, thisprogressive reduction in spacing will ordinarily not be given to thepump.

The figures represent a pump for use with air, the inlet openingreceiving the air directly from the surrounding room. It is of courseevident that when used for other fluids than air suitableprovision ismade for connecting to a supply pipe.

Passages 60 communicating with the liquid-receiving heat-treatingchambers 29 and 30 in the semi-cylindrical casting to overflow at anyconvenient place. Where the temperature control medium is steam the pan51 would be closed at the top but I have not considered'it necessary toillustrate this as it is merely the'obvious means for keeping the steamfrom escaping into the surrounding air and for maintainin it in intimatecontact with the surface of the central casing.

Where the construction of the outer semicylindrical membels and themiddle. mem' bar is sectional with flanged sectional castings boltedtogether, I prefer to locate the lines of division across thecorresponding ends of successive pairs of impellers, and to form thegland housings integral with the adjoining end sections. Either or bothof the end sections may be provided with semicylindricalcompartments'for temperature control.

When used as an air compressor, as in the form illustrated, coolin willusually not be begun until after the rst stage and in the figures nocooling compartments areshown until after the first stage impellers; butwhen the duty is to be that of furnishing a high pressure supply ofviscous liquid such as molasses it may be desirable to have thesecompartments or temperature control before the first stage as well asafter the last.

The successive sections bolt together along radial flanges and bolt tothe middle member 34 along longitudinal flanges 66.

Each pair of mating impellers, with its casin may be considered ascompr1s1ng a comp ete single stage pump, the impellers of which exactlfit and seal against the inner walls of 1ts lateral semi-cylindricalpocket, against its mate and against the transverse partition walls 67and 68 across the middle member 34'.

Walls 67 are closed to the floor with easy curves at 69 and Walls 68closed to the roof with eas curves at 70 to form the series conduitetWeen the outlets and inlets respectively of successive stageimpellers.

It will be evident that these easy curves at 69 and 70 result at once invery low frictional resistance from pump to pump and also provide spacesfor the transverse passages 52 and 63 and a large bottom area for thereservoir 51.

In operation the shaft 19 is driven in any suitable way, and this inturn by means of the intermeshing gears 41 and 41 main tains theseshafts and the mating pairs of impellers in synchronous rotation.

The pumped fluid, as air, progressively travels from the inlet of thefirst stage to the outlet from the last with progressive increase inpressure at each stage; and while thus progressing through the multistages its temperature is regulated by surface contact with and surfaceradiation from the inner walls of the compartments for temperaturecontrol, the temperatures being progressively lowered or progressivelyraised according to existing need by controlling the wall temperature ofthe compartments through control of the temperature and rate of flow ofa suitable fluid through these compartments. 1 7

While I have elected to illustrate but a single form, it will be obviousto those ski led in the art that the preferred form in any installationwill vary with conditions of service, as for example with the presenceor absence of need for tem erature regulation betweenista-ges'; with t efluid -medium used (e. g. water or stem'n) for temperature regulation,or with any individual whim or particular need, varying andmodifyingthestructure and I intend to claim all such variations and modifieations inso far as they fall within the. zeasonable spirit and scope of my inven-Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is i 1. A multi-stage pump comprising a pair ofsingle stage rotary pumps 'Root type, spaced axially of their parallelshafts to provide a space between them to art. as a channel, wallscompleting the limits of the channel and establishing communicationbetween opposite extremities of said-channel and the outlet of one pumpcompartment and the inlet of the other, respectively, and means forheat-treating the fluid as it passes through the pump.

2. A pair of single stage Root type rotary pumps spaced axially of theirparallel shafts, having the parts between the shafts in one piece and toprovide a space between them as a channel, walls completing the channeland establishing communication from the outlet of one channel to theinlet of the other, said walls forming separate semicircumferential sidemembers for earh of the two pumps, securing rigidity of the unit by thecentral member and permitting removal of the walls forming the sidemembers for repairs and shaft replacement.

3. A pair of single stage Root type rotary pumps spaced axially of theirparallel shafts,to provide a space between them as a channel, wallscompleting the channel and establishing communication from the out letof one channel to the inlet of the other,

said pumps and walls separating along longitudinal planes passingthrough the parallel shafts into middle portions and semicylindricalside portions, in combination with walls forming fluid receivingheattreating chambers in the said cylindrical side portions.

4. A pair of single stage Root type pumps spaced axially of theirparallel shafts, to provide a space between them as a channelcommunicating from the outlet of one to the inlet of the other andhaving the pumps and the walls of the channel se arated alonglongitudinal planes passing t rough the parallel shafts into middleportions and semicylindrical side portions, in combination with wallsforming compartments for heatchannel to affect the fluid pumped during.

- parallel s afts upon which the imellers are its passage from one pumpto the next.

5. Two rotary ressure pumps relatively spaced and axial y in line, incombination with an intermediate section, comprising in its central partwalls combining with the pumps to provide a passage from the inlet ofone pump to the outlet of the other and in its outer arts walls forminga heat-treating section or the liquid pumped.

6. Two rotary pressure pumps, relatively spaced and axially in line, comrising two pairs of synchronously rotating impellers of the Root typewithin casings and on parallel shafts, in combination with anintervening conduit section included between the pumps and receiving at.one side the discharge of one pump and at an opposite side of the casingand of the conduit feeding the inlet of the other pump, and meansincluded between the pumps for regulating the temperature of theconduit. section.

7. Two rotary pumps, relatively spaced and axially in line, comprisingtwo pairs of synchronously rotating impellers within casings and onparallel shafts and an intervening conduit section included between thepumps, receiving, at one side of the casing and of the conduit thedischarge of one pump and at an opposite side of the conduit and of thecasing feeding the inlet of the other pump, in combination withcompartments included between the pumps for fluid regulation of thetemperature of the conduit.

8. A multistage pump, comprising a plurality of spaced pump sectionseach having a box-like central casing member between twosemi-cylindrical side casings, a pair of parallel shafts within thesections and common to the several pumps, mating impellers of the Roottype synchronously rotating and sealing against the end walls of therespective central casing member, with each other and with the walls ofthe semi-cylindrical side casing members, fluid compartments fortemperature control carried by the semi-cylindrical side casing membersand between adjoining pump sections, and extensions of the end wallsbetween the central casing members of adjoining pump sections closing atone end of each wall and forming between the sectionsa chamber conduitbetween the outlets and inlets of the respective pump sections.

9. A multi-stage pump having a plurality of pairs of mating impellers ofthe Root type spaced along one pair of shafts and casing walls for eachpair of mating impellers, 1n combination with walls uniting the casingwalls of adjoining pairs of impellers to form between the shafts aconduit chamber to receive the discharge of one pair of impellers fordelivery to the next pair, and to form outside of each shaft acompartment adapted to fluid regulation of temperature.

10. A air of impellers of the Root type mounted, a casin for theimpelers comprising semi-cylin rical side sections-at opposite sides ando en'at one end transverse to the shafts an an intermediate sectionjoinin 'them, in combination with another pair 0 impellers of the Roottype mounted on the same shafts and spaced from the first, an impellereasing surrounding the second pair of impellers and havin a straightsection between the shafts an semi-cylindrical side sections and each ofthe latter side sections having a semi-cylindrical fluid compartment fortemperature regulation closing the open end of one of the firstsemicylindrical side casings sections on one side and easing one of thesecond im ellers upon the other, and closure walls etween the straightcasing sections formin conduit connection between the outlet 0 ofimpellers and the inlet of the other pair of impellers.

11. A air of impellers of the Root type, parallel s rafts upon which theimpellers are mounted, a casing for the impellers comprising a straightsection between the shafts and semi-cylindrical side sections atopposite sides and each open at one end transverse to the shafts, incombination with a plurality of pairs of impellers of the Root typespaced from the first pair and from one another along the same pair ofparallel shafts, a casing for each additional pair having a straightsection between the shafts and semi-cylindrical side sections at op 0-site sides, each semi-cylindrical side sectlon having one end transverseto the shafts open and at the other end a semi-cylindrical extensionforming a water cooling compartment adapted to case its own impellerupon one side and to close the open end of an adjoining semi-cylindricalcasing upon the other, and closure walls joining successive straightsections to form conduit connection between the outlet and inlet ofadjoining pairs of impellers.

12. A multi-stage blower comprising a plurality of complete Root typeblowers spaced alon and upon the same pair of shafts and dlvidedtransversely to the shafts along planes at the ends of the impellersproviding sections having open and closed ends, considered in directionsparallel to the shafts, the open end of one section being closed by theclosed end of the next.

13. A semi-cylindrical side casing member for a pump of the Root typecomprising a semi-cylindrical casing adapted to fit the revolving bladesof one of the impellers, in combination with a fluid compartment fortemperature regulation in line with the casing in a direction parallelto the impeller shaft.

14. A semi-cylindrical side casing memone pair her for a pump of theRoot type having along the impeller shaft one closed end and one openend, in combination with a second semi-cylindrical side casing memberfor a second and eo-axial pump of the Root type having along theimpeller shaft :1 fluid chamber for temperature regulation form ing oneend of its own impeller casing and adapted to close the open end of thefirst impeller casing.

spective spaced impellers along one of the I common shafts and theintermediate compartment adapted to fluid regulation of temperature.

THOMAS W. GREEN.

